Method and system for analyzing an image generated by at least on camera

ABSTRACT

A method for analyzing an image of a real object, generated by at least one camera includes the following steps: generating at least a first image by the camera capturing at least one real object, defining a first search domain comprising multiple data sets of the real object, each of the data sets being indicative of a respective portion of the real object, and analyzing at least one characteristic property of the first image with respect to the first search domain, in order to determine whether the at least one characteristic property corresponds to information of at least a particular one of the data sets of the first search domain. If it is determined that the at least one characteristic property corresponds to information of at least a particular one of the data sets, a second search domain comprising only the particular one of the data sets is defined and the second search domain is used for analyzing the first image and/or at least a second image.

This application is a continuation of U.S. patent application Ser. No.13/128,372 filed Aug. 1, 2011, which application claims the benefit ofand incorporates by reference essential subject matter disclosed in PCTApplication No. PCT/EP2008/009481 filed on Nov. 10, 2008.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention is directed to a method and system for analyzingan image generated by at least one camera, wherein the at least oneimage is generated by the camera capturing at least one print mediaobject.

2. Background Information

In the prior art there are known applications which augment print mediaobjects, such as conventional books, with virtual objects using the socalled Augmented Reality (AR) technology: H.K.U.I.P. Mark Billinghurst,The Magic Book: A transitional AR interface, Computers and Graphics,25(5), 2001, pages 745-753 and John McKenzie and Doreen Darnell, TheeyeMagic Book—A Report into Augmented Reality Storytelling in theContext of a Children's Workshop, 2003.

In such application, a camera coupled to a computer takes a picture of abook read by a person, wherein the book is displayed on a display screenand virtual objects may be displayed in addition to the image of thereal world containing the book, so that the book displayed on thedisplay screen is augmented with virtual objects of any kind on adisplay screen. In such application, in order to augment the image withvirtual objects, there is the need for the computer system to identifythe real object, such as a respective page of the book, and its positionand orientation with respect to the camera in order to correctly displaythe virtual object in the image taken by the camera.

Generally, each double page, i.e. the pages of the book which aresimultaneously visible when reading the book, is represented by arespective data set stored in the computer system. When the book ispositioned with an opened double page on a table, for example, and thecamera is taking an image of the book, the image of the camera iscapturing the double page opened in front of the camera. For identifyinga particular double page of the book in order to correctly display thevirtual object in the image of that double page, the computer system isrequired to compare one or more features of the image taken by thecamera with all of the data sets stored in the computer system for thebook, which process is rather time consuming and requires largeprocessing performance of the computer system.

It is therefore an object of the invention to provide a method and asystem for analyzing an image of a real object generated by at least onecamera which may be performed with reduced processing requirementsand/or at a higher processing speed.

SUMMARY OF THE INVENTION

The invention is directed to a method according to the features of claim1. Additionally, the invention is directed to a system according to thefeatures of claim 12 and a computer programmable product according toclaim 13.

According to a first aspect of the invention, there is disclosed amethod for analyzing an image of a real object generated by at least onecamera, wherein the method comprises the following steps: generating atleast a first image by the camera capturing at least one real object,defining a first search domain comprising multiple data sets of the realobject, each of the data sets being indicative of a respective portionof the real object, and analyzing at least one characteristic propertyof the first image of the camera with respect to the first searchdomain, in order to determine whether the at least one characteristicproperty corresponds to information of at least a particular one of thedata sets of the first search domain. If it is determined that the atleast one characteristic property corresponds to information of at leasta particular one of the data sets, the method includes the step ofdefining a second search domain comprising a reduced number of the datasets compared to the first search domain and using the second searchdomain for analyzing the first image and/or at least a second imagegenerated by the camera.

Therefore, the method provides the advantage that for analyzing at leasta second and following images generated by the camera, any predefinedsearch domain used for analyzing the images may be significantly reducedto a smaller size, particularly to comprise only the data set or datasets for which a previous correspondence has been found, so that lessprocessing power is needed for the analyzing process and/or theprocessing speed can be increased.

An embodiment of the invention comprises that the real object is aprinted media object which is an advantageous object for which thepresent invention may be applied.

The invention advantageously uses the inventors' finding that in certainapplications all portions of a real object, such as all pages of a book,cannot be captured by the camera simultaneously. Rather, with taking animage of a real object, such as a book, only a particular portion ofthat object, such as a particular double page of a book, can be capturedat a time by the camera. The invention uses this finding in that thesearch domain for the following analyzing process is reduced to areduced number of data sets once it has been found that there is acorrespondence between at least one characteristic property of thecurrent image and a particular one of the data sets.

Embodiments of a printed media object as understood in the context ofthe present invention include, for example, a book, a printed magazine,a newspaper, a catalog, a folder or any other type of device used in thesame or a similar way or for the same or a similar purpose. Generally, aprinted media object, as may be used with the present invention, may bea printed, substantially flat or even object comprising one or moreprinted pages which may be turned over by a user from one page or doublepage to another page or double page, respectively, and may be positionedin front of a camera. The invention may also be applied to other typesof real objects having portions and corresponding data sets which arenot visible simultaneously.

Particularly, the method includes the step of analyzing at least onecharacteristic property of the second image of the camera with respectto the second search domain, in order to determine whether the at leastone characteristic property of the second image corresponds toinformation of a particular one of the data sots of the second searchdomain.

According to an embodiment of the invention, the method further includesthe step of setting a time period or a number of images captured by thecamera for analyzing following images with respect to the second searchdomain, and if it is determined that none of characteristic propertiesof the following images corresponds to information of a particular oneof the data sets of the second search domain within the set time periodor within the number of captured images, the first search domain is usedfor analyzing at least one further image captured by the camera.Therefore, if the user is changing, for example, to another double pageof the book so that the system. cannot find a correspondence for thatdouble page in the second search domain, again the first search domainis used for analyzing the new image in order to find another particularone of the data sets corresponding to that double page.

For example, each of the data sets is indicative of a respective page ordouble page of the printed media object. This embodiment uses thefinding that under normal circumstances only two pages of a double pageof the printed media object are visible simultaneously, so that thesearch domain can be reduced accordingly.

The invention, in an embodiment thereof, may be used for augmenting oneor more of the images with one or more virtual objects, so that anaugmented reality system needs less processing power and/or may operatewith higher processing speed. Accordingly, the method may include thesteps of displaying the first and second images on image displayingmeans, wherein the at least one of the images is augmented with at leastone virtual object using an Augmented Reality technology.

A further aspect of the invention is concerned with a system foranalyzing an image, comprising a camera for generating at least a firstand second image capturing at least one real object, and a processingunit connected with the camera. The processing unit is programmed forperforming the steps of defining a first search domain comprisingmultiple data sets of the real object, wherein each of the data sets isindicative of a respective portion of the real object, and analyzing atleast one characteristic property of the first image of the camera withrespect to the first search domain, in order to determine whether the atleast one characteristic property corresponds to information of at leasta particular one of the data sets of the first search domain. If it isdetermined that the at least one characteristic property corresponds toinformation of at least a particular one of the data sets, a secondsearch domain is defined comprising only the particular one of the datasets. This second search domain is then used for analyzing the firstimage and/or at least a second image generated by the camera.

Further embodiments and aspects of the invention are evident from thedependent claims.

The invention will now be described in more detail in conjunction withthe accompanying drawings which illustrate various embodiments of theinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic illustration of a first embodiment of a systemaccording to the invention;

FIG. 2 shows a schematic illustration of a second embodiment of a systemaccording to the invention;

FIG. 3 shows a schematic illustration of portions of a printed mediaobject and data sets indicative of respective portions of the printedmedia object,

FIG. 4 shows a flowchart illustration of a method according to anembodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

In FIG. 1 there is shown a schematic illustration of a first embodimentof a system according to the invention. Particularly, FIG. 1 shows asystem 1 in which a user 10 holds a camera 11 in his or her hand forgenerating at least one image of the real world, for example of the realobject 12 as shown, which is in the present example a printed mediaobject of the type as described herein before. According to a particularexample, the real object 12 may be a book which is placed in front ofthe user 10, and the camera 11 takes an image of the book 12 to bedisplayed on a display screen. The book 12 is provided with an objectcoordinate system 17, such as shown in FIG. 1. Further, the camera 11 iscoupled with an image displaying means 13, such as a display screen of apersonal computer, or the like. However, any other image displayingmeans may be used which is suitable for displaying an image to a user,such as a head mounted display or any other type of mobile or stationarydisplay device. Furthermore, a processing unit 14, which may be forexample a personal computer (PC), is connected with the camera 11 andthe image displaying means 13 in wired or wireless fashion. Theinvention is applicable to embodiments where the camera 11, theprocessing unit 14 and/or the displaying means 13 are integrated in anapparatus or are distributed components. For example, the camera 11, theprocessing unit 14 and/or the displaying means 13 may be integrated in asingle apparatus such as a mobile phone.

In the situation as shown in FIG. 1 the user holds the camera 11 in hisor her hand and is looking at the object 12 placed in front of the user.The camera images, such as a video flow of images, are displayed on theimage displaying means 13 placed in front of the user 10. According toan embodiment of the invention, the images may be augmented with one ormore virtual objects according to the augmented reality (AR) technology.According to a possible application, the user 10 is taking pictures or avideo stream of a book 12, and on the image displaying means 13 theimages of the book 12 are shown augmented with virtual information, suchas a 3-dimensional virtual illustration of a 2-dimensional objectprinted on a double page of the book 12 and captured by the camera 11(typical magic book application as described above).

In FIG. 2, there is shown another situation in which the system 1substantially comprises the same components as described with referenceto FIG. 1, however, in a different configuration. In the situation asshown in FIG. 2, the camera 11 is arranged opposite to the user 10, forexample in front of the user 10 on an image displaying means 13, such asa display screen. By means of the camera 11, the user 10 may take imagesof a real object 12, such as a book, held in the user's hands or placedon a table in front of the user. The real object 12 is provided with anobject coordinate system 17 similar as in FIG. 1. In the situation asshown in FIG. 2, the user 10 may move the book 12 with his or her handsin front of the camera 11, wherein the images taken by camera 11 aredisplayed as images on the display screen 13.

The image or images by the camera 11 are transmitted to the processingunit 14 which is adapted for performing an image analyzing processaccording to an embodiment of the present invention. Particularly, theprocessing unit 14, such as a PC, includes a computer program producthaving software code sections which are adapted for carrying out theprocess according to the invention, when the code sections are loadedinto an internal memory of the PC 14. For example, the software codesections may be stored in an internal memory of the PC or may beprovided on a hard disc or any other suitable storage means, wherein theprogram is loaded into the internal memory of the computer duringoperation. The camera data may be transmitted to the PC 14 in wired orwireless fashion.

Taking the magic book application as a particular exemplary embodimentof the invention, in order to augment the image with one or more virtualobjects, there is the need for the processing unit 14 to identify thereal object 12, such as a respective page of the book, and the positionand orientation of its coordinate system 17 with respect to the camera11 in order to correctly display the virtual object in the image takenby the camera. For this purpose, image processing and trackingalgorithms, such as marker-based or markerless tracking algorithms, maybe applied which are well known in the art, particularly in theaugmented reality technology.

Generally, when the camera 11 is taking a picture of the book 12, twopages of an opened double page are visible and can be viewedsimultaneously. In order to identify the opened double page of the book12 and its position and orientation, the system has to identify at leastone characteristic property of the double page, such as a characteristicfeature of the respective double page, which distinguishes this doublepage from another double page of the same book 12. For this purpose, asillustrated in FIG. 3, each double page, i.e. the pages of the book 12which are simultaneously visible when the book is opened in front of theuser, is represented by a respective data set stored in the processingunit 14. For example, a left page P1 and a right page P2 of the book 12are forming a first double page P1/P2 which is represented by the dataset S1. In other words, the data set S1 is indicative of the double pageP1/P2, thus contains data or information which allows the processingunit 14 to identify the double page P1/P2 and its position andorientation (pose).

In an embodiment of the invention, the data set S1 may include twosubsets S1 a, S1 b, with subset S1 a being indicative of page P1 andsubset S1 b being indicative of page P2 of the book 12. In this regard,the data set S1 may include, in principal, any number of subsets.

Similarly, as the reader turns the page 1 of the book 12, the followingpages P3 and P4 of the book 12 are forming a second double page P3/P4which is represented by the data set S2, so that the data set S2 isindicative of the double page P3/P4 and its pose relative to the camera11. Likewise, the data sets S3 to S5 are indicative of the double pagesP5/P6, P7/P8 and P9/P10, respectively. Like data set S1, data sets S2 toS5 may also contain subsets S2 a to S5 b for each of the pages P3 to P10as shown in FIG. 3. The organization of the pages and respective datasets and the number thereof is only described as a particular example,wherein the skilled person will appreciate that also other types of datastructures may be used for the purposes of the invention.

When the book is positioned with an opened double page, such as P1/P2 ona table, for example, and the camera 11 is taking a first image 15 ofthe book 12, the image 15 displayed on the display screen 13 iscapturing the double page P1 /P2 opened in front of the camera 11. Foridentifying this double page P1/P2 of the book in order to correctlydisplay a virtual object in the image 15 of that double page, theprocessing unit 14 is required to compare one or more features of theimage 15 taken by the camera 11 with all of the data sets S1 to S5stored in the processing unit 14 for the book 12, which process israther time consuming and requires large processing performance of thecomputer system.

A particular aim of the present invention is to provide a methodologyfor analyzing an image of a real object, such as the book 12, generatedby a camera which may be performed with reduced processing requirementsand/or at a higher processing speed.

According to FIG. 4, there is illustrated a flow chart of an embodimentof an analyzing process according to the invention which may beimplemented in the processing unit 14 of the system 1 as shown in FIGS.1 and 2.

The process starts with step 1 for defining a first search domain D1intended to be used for analyzing at least a first image 15 taken by thecamera 11. In the present example, the first search domain D1 comprisesthe multiple data sets S1-S5 of the book 12 as described above withrespect to FIG. 3. Particularly, the search domain D1 comprises themaximum number of data sets available for the book 12, which are in thepresent case data sets S1 to S5. This is because the processing unit 14does not know which of the double pages of the book is opened.

In step 2, the camera 11 is taking a first image 15. The search domainbeing at maximum size, the processing unit 14 in step 3 has to analysethe image 15 with respect to all data sets S1 to S5 in order to find aparticular one of the data sets S1 to S5 or S1 a to S5 b, respectively,which corresponds to the opened double page or at least one of theopened pages. The processing unit 14 analyses at least onecharacteristic property, such as a characteristic feature of the firstimage 15 of the camera with respect to the first search domain D1. Theresult of the analyzing process is to determine whether the foundcharacteristic property corresponds to information of at least aparticular one of the data sets S1-S5 (or S1 a to S5 b, respectively) ofthe first search domain D1. Particularly, the processing unit 14 mayperform a feature detection algorithm within a markerless trackingprocess to identify whether any found characteristic feature of theimage 15 corresponds to information, such as features F1 to F3 shown inFIG. 3, stored in the data set S1. If no such correspondence is found,the processing unit 14 changes to data set S2 and so on until it isdetermined whether any one of the data sets S1 to S5 corresponds to theimage 15.

In case that the found characteristic feature of image 15 corresponds toinformation of at least a particular one of the data sets S1 to S5 (step4), a second search domain D2 is defined comprising, in the presentembodiment, only the particular one of the data sets S1 to S5 (step 5),or particular ones of the data sets S1 a to S5 b, respectively. In thepresent example where each of the data sets comprises multiple data(sub-)sets, the second search domain D2 is defined to comprise only thedata sets (e.g. data sets S1 a, S1 b) being indicative of at least apart of the particular double page (such as P1/P2) comprising the foundcharacteristic feature. In this regard, it is not required that all datasets of a double page be included in the search domain D2, rather themost significant ones may be sufficient.

For example, if it is determined that the found characteristic featureof image 15 corresponds to feature F2 of data set S1 (particularly dataset S1 a), the second search domain D2 is defined to comprise only theparticular data set S1 (including data sets S1 a, S1 b), as shown inFIG. 3. This second search domain D2 is used for analyzing the firstimage 15 and/or at least a following second image 16 generated by thecamera 11 (returning to step 2), as it is supposed that the user isremaining for a while reading the double page P1/P2 without changingquickly to any other double page. Thus, for the further analyzingprocess the search domain is reduced significantly. In the presentexample, once the feature F2 of data subset S1 a has been identified,the system only has to search for the other subset S1 b of the data setS1 defining the reduced search domain D2.

In an embodiment of the invention, the search domain D2 may alsoinclude, for example, the data set of one or more adjacent double pages,such as data set S2 in order to be prepared if the user turns page P2 toview double page P3/P4. Also, the search domain D2 may be iterativelyexpanded to data sets covering adjacent double pages, after having notidentified a particular data set for a certain period of time or acertain amount of images captured and analyzed.

For example, if the user moves the book 12 or double page P1/P2 in aplane parallel to the table, the system can quickly follow this movementas the processing unit 14 is analyzing the following images only withrespect to data set S1. Thus, the processing unit 14 can quicklyassociate features of the following images with corresponding featuresof the data set S1. Here, the invention makes use of the fact that theother double pages P3/P4, P5/P6 and so on cannot be seen by the user ifdouble page P1/P2 has once been identified as being opened in front ofthe camera 11.

For example, a time period may be set for analyzing the second image 16or any following image with respect to the second search domain D2 (step6). In case that, within the set time period, it is determined that therespective image does not correspond to information of a particular dataset comprised in the second search domain D2 (in the present example,data set S1), i.e. a particular data set of the second search domain D2is not identified (step 4), the first search domain D1 having themaximum number of available data sets S1 to S5 is used for analyzing therespective or following images. This case can occur, for example, if theuser turns the page P2 to view another double page which corresponds toanother one of the data sets S1 to S5. In this case, the processing unit14 has to search in the search domain D1 again in order to identify thecorresponding data set.

Generally, according to the invention, objects belonging together (i.e.which are visible simultaneously), such as pages of a respective doublepage, may be grouped to a respective data set, which data sets excludeone another. If an element of a particular group or data set is visible,then elements of other groups or data sets cannot be visible, thus canbe excluded when forming the second search domain.

An advantage of the invention is that the system is capable of reducingthe search domain for analyzing an image of the camera. Once the systemknows which group is captured by the camera, the system only searchesfor features of that particular group. For example, if a feature orportion of a particular double page has been found, the system onlysearches for other portions of the particular double page, and does notsearch for all of the other double pages of the book.

In an embodiment of the invention, the method may further include thatthe step of analyzing an image with respect to the first search domainincludes a first algorithm and analyzing an image with respect to thesecond search domain includes a second algorithm, which is differentfrom the first algorithm.

Particularly, it is advantageous if the first algorithm requires a lessmemory-intensive data structure for matching of features than the secondalgorithm.

Many different feature descriptors are known in the state of the art.Each descriptor, its extraction and matching algorithms have differentadvantages and disadvantages. For example, one descriptor might functionby generating an optimized data structure, storing the characteristicsof a specific feature from many different views and being able to findand match a feature, relying on that data structure being present in thememory of the processing unit. These algorithms are usually limited inthe number of features they can use by the physical memory available.

Other algorithms try to calculate a compact representation of a feature,which invariant to different camera positions, light changes and otherfactors. They usually need less memory to describe a feature, but thedescription has to be calculated from every frame in the image, oftenusing a lot of processing power.

One aspect of the invention is the possibility to apply a sloweralgorithm with a smaller memory footprint for a large dataset offeatures and to apply a faster algorithm with a larger memory footprint,once the search domain is reduced.

Algorithms with smaller memory footprints are for example: David G.Lowe, “Distinctive image features from scale-invariant keypoints”,International Journal of Computer Vision, 60, 2 (2004), pp. 91-110 andHerbert Bay, Tinne Tuytelaars, Luc Van Gool, “SURF: Speeded Up RobustFeatures”, Proceedings of the ninth European Conference on ComputerVision, May 2006 and Mikolajczyk, K., Zisserman, A. and Schmid, C.,Shape recognition with edge-based features Proceedings of the BritishMachine Vision Conference (2003).

Algorithms with larger memory footprints are for example: V. Lepetit, P.Lagger and P. Fua, Randomized Trees for Real-Time Keypoint Recognition,Conference on Computer Vision and Pattern Recognition, San Diego,Calif., June 2005 and S. Hinterstoisser, S. Berihimane, N. Navab, P.Fua, V. Lepetit, Online Learning of Patch Perspective Rectification forEfficient Object Detection, IEEE Computer Society Conference on ComputerVision and Pattern Recognition, Anchorage, Ak. (USA), June 2008.

While the invention has been described with reference to exemplaryembodiments, it will be understood by those skilled in the art thatvarious changes may be made without departing from the scope of theclaims.

1. A method, comprising: obtaining a first image captured by a camera,the first image comprising at least one real object; defining a firstsearch domain comprising a plurality of data sets corresponding to theat least one real object; analyzing at least one characteristic propertyof the first image to identify a particular one of the plurality of datasets of the first search domain; defining a second search domaincomprising at least the particular one of the plurality of data sets,wherein the second search domain is reduced from the first searchdomain; obtaining a second image generated by the camera; and analyzingat least one characteristic property of the second image using thesecond search domain to determine whether the at least onecharacteristic property of the second image corresponds to informationof a data set of the second search domain.
 2. The method of claim 1,wherein analyzing at least one characteristic property of the secondimage comprises: determining that the second image was captured within apredetermined time period of the first image; and in response todetermining that the second image was captured within a predeterminedtime period of the first image, analyzing the at least onecharacteristic property of the second image using the second searchdomain.
 3. The method of claim 1, further comprising: determining thatthe at least one characteristic property of the second image does notcorrespond to information of a particular one of the plurality of datasets of the second search domain; and in response to determining thatthe at least one characteristic property of the second image does notcorrespond to information of a data set of the second search domain,analyzing the at least one characteristic property of the second imageusing a third data set of the first search domain.
 4. The method ofclaim 3, wherein the first data set and the third data set correspond toportions of the object that cannot be seen concurrently.
 5. The methodof claim 4, wherein the object is a printed media, and wherein the firstdata set corresponds to a first set of adjacent pages in the printedmedia and wherein the third data set corresponds to a second set ofadjacent pages in the printed media.
 6. The method of claim 5, whereinthe second search domain comprises a plurality of data setscorresponding to contiguous sets of adjacent pages.
 7. The method ofclaim 1, further comprising: displaying the first image and the secondimage on a display device, wherein at least one of the first image andthe second image is augmented with at least one virtual object using anaugmented reality technology.
 8. A computer readable medium comprisingcomputer readable code which, when executed by one or more processors,causes the one or more processors to: obtain a first image captured by acamera, wherein the first image comprises at least one real object;define a first search domain comprising a plurality of data setscorresponding to the at least one real object; analyze at least onecharacteristic property of the first image to identify a particular oneof the plurality of data sets of the first search domain; define asecond search domain comprising at least the particular one of theplurality of data sets, wherein the second search domain is reduced fromthe first search domain; obtain a second image generated by the camera;and analyze at least one characteristic property of the second imageusing the second search domain to determine whether the at least onecharacteristic property of the second image corresponds to informationof a data set of the second search domain.
 9. The computer readablemedium of claim 8, wherein the computer code to analyze at least onecharacteristic property of the second image comprises computer code to:determine that the second image was captured within a predetermined timeperiod of the first image; and in response to determining that thesecond image was captured within a predetermined time period of thefirst image, analyze the at least one characteristic property of thesecond image using the second search domain.
 10. The computer readablemedium of claim 8, further comprising computer code to: determine thatthe at least one characteristic property of the second image does notcorrespond to information of a particular one of the plurality of datasets of the second search domain; and in response to determining thatthe at least one characteristic property of the second image does notcorrespond to information of a particular one of the plurality of datasets of the second search domain, analyze the at least onecharacteristic property of the second image using a third data set ofthe first search domain.
 11. The computer readable medium of claim 10,wherein the first data set and the third data set correspond to portionsof the object that cannot be seen concurrently.
 12. The computerreadable medium of claim 11, wherein the object is a printed media, andwherein the first data set corresponds to a first set of adjacent pagesin the printed media and wherein the third data set corresponds to asecond set of adjacent pages in the printed media.
 13. The computerreadable medium of claim 12, wherein the second search domain comprisesa plurality of data sets corresponding to contiguous sets of adjacentpages.
 14. The computer readable medium of claim 8, further comprisingcomputer code to: display the first image and the second image on adisplay device, wherein at least one of the first image and the secondimage is augmented with at least one virtual object using an augmentedreality technology.
 15. A system comprising: a camera; one or moreprocessors; and a storage device comprising computer readable codewhich, when executed by the one or more processors, causes the one ormore processors to: obtain a first image captured by the camera, whereinthe first image comprises at least one real object; define a firstsearch domain comprising a plurality of data sets corresponding to theat least one real object; analyze at least one characteristic propertyof the first image to identify a particular one of the plurality of datasets of the first search domain; define a second search domaincomprising at least the particular one of the plurality of data sets,wherein the second search domain is reduced from the first searchdomain; obtain a second image generated by the camera; and analyze atleast one characteristic property of the second image using the secondsearch domain to determine whether the at least one characteristicproperty of the second image corresponds to information of a data set ofthe second search domain.
 16. The system of claim 15, wherein thecomputer code to analyze at least one characteristic property of thesecond image comprises computer code to: determine that the second imagewas captured within a predetermined time period of the first image; andin response to determining that the second image was captured within apredetermined time period of the first image, analyze the at least onecharacteristic property of the second image using the second searchdomain.
 17. The system of claim 15, further comprising computer code to:determine that the at least one characteristic property of the secondimage does not correspond to information of a particular one of theplurality of data sets of the second search domain; and in response todetermining that the at least one characteristic property of the secondimage does not correspond to information of a particular one of theplurality of data sets of the second search domain, analyze the at leastone characteristic property of the second image using a third data setof the first search domain.
 18. The system of claim 17, wherein thefirst data set and the third data set correspond to portions of theobject that cannot be seen concurrently.
 19. The system of claim 18,wherein the object is a printed media, and wherein the first data setcorresponds to a first set of adjacent pages in the printed media andwherein the third data set corresponds to a second set of adjacent pagesin the printed media.
 20. The computer readable medium of claim 15,wherein the system further comprises a display device, and wherein thecomputer code further causes the one or more processors to: display thefirst image and the second image on a display device, wherein at leastone of the first image and the second image is augmented with at leastone virtual object using an augmented reality technology.